The problematic part of documentation is the bleow in 6.2. Configuring shared instance storage.

2. Add the required configuration or modify the existing configuration under ansibleVars:

apiVersion: dataplane.openstack.org/v1beta1
kind: OpenStackDataPlaneNodeSet
metadata:
name: my-data-plane-node-set
spec:
...
  nodeTemplate:
    ansible:
      ansibleVars:
        edpm_bootstrap_command: |
          dnf -y install conntrack-tools
        edpm_extra_mounts:
        - fstype: nfs4
          opts: context=system_u:obje/var/lib/nova/instances <=======(*)
          path: /var/lib/nova/instances
          src: <nfs_path>

`context=system_u:obje/var/lib/nova/instances` is not a correct value for `opts:` parameter.
It should be `opts: context=system_u:object_r:nfs_t:s0` instead.